Urethral catheters are used extensively for bladder drainage, in cases of patient incontinence or when, for any reason, the patient cannot release urine from his/her bladder, for example, because of a constriction in the urethra. The catheter is introduced into the bladder via the urethra which, in the male, is a relatively tortuous tube of varying cross-sectional dimensions and which is normally collapsed along most of its length. The upper portion of the urethra has sphincters or valves where it enters the bladder at the bladder neck. In addition, in the male the prostate gland is located at the juncture of the urethra with the bladder. If the prostate is enlarged, it may cause tile urethra to be constricted and entry of the catheter into the bladder may be impeded. In addition, if the prostate has become enlarged it may protrude inwardly into the bladder, forming an obstruction at the top of the urethra and making it even more difficult to insert a catheter into the bladder.
When a conventional, straight catheter is inserted into the urethra of a male under conditions of an enlarged prostate, the catheter tip is sometimes blocked by the protrusion of the prostate into the bladder, making it difficult to further insert the catheter. Catheters have been developed which have curved tips which are better able to avoid the protruding prostate and successfully guide the catheter into the bladder.
Curved tip catheters are almost twice as expensive as straight tip catheters and thus the tendency of the health care worker in hospitals and other locations is to first attempt insertion of a straight tip catheter on the patient. If it is impossible to insert the straight tip catheter, the catheter is discarded and a curved tip catheter is used and the procedure is repeated. The result is that the straight tip catheter is wasted and additional time is required to repeat the procedure.
Typically, a multitude of different sizes of catheters should be available to the health care worker. Catheters of varying diameters are used to provide for the desired flow rate of the of the discharge through the catheter. In addition to the multitude of different sizes, both curved tip and straight tip catheters in the various sizes typically should be available to the health care worker.
It would be desirable to have accessible to the health care worker a multiple purpose catheter having either straight or curved tips so as to reduce the required supply of catheters available to the health care worker and to reduce the costs required to supply catheters of various sizes and shapes.
The prior art teaches catheters formed from a tip and a shaft. See, for example, U.S. Pat. Nos. 4,361,152 to Patel, 4,222,384 to Birtwell, 3,890,976 to Bazell et al., and 3,832,253 to Di Palma et al. The catheters taught in these patents are designed to be assembled or manufactured at a manufacturing facility, not on-site in a hospital or emergency setting. U.S. Pat. No. 3,094,124 to Birtwell teaches an arterial catheter wherein tips of various diameters can be attached to a shaft. In this manner, abrupt changes in diameter can be avoided and blood flow is smoother. However, this patent does not teach a curved tip urethral catheter and the tip is attached to the shaft merely by friction. Thus, there is the possibility that the tip may become dislodged and disconnected from the shaft.